tslint-language-service

TypeScript language service plugin for tslint.

To use it the plugin:

• install the plugin with npm install tslint-language-service

• enable the plugin in your tsconfig.json file:

{
  "compilerOptions": {
    "plugins": [
      { "name": "tslint-language-service"}
    ]
  }
}

• If you are using TypeScript < 2.2.1, you must execute tsserver with tsserver-plugins.

Your node_modules folder should look like this:

• node_modules
  • tslint
  • tslint-language-service
  • typescript

Notice due to an issue in the implementation of the no-unused-variable rule ([issue2469]), this rule will be disabled by the plugin. You can use the typescript compiler options noUnusedLocals and noUnusedParameters instead.

Configuration options

Notice this configuration settings allow you to configure the behaviour of the tslint-language-service plugin. To configure rules and tslint options you should use the tslint.json file.

• configFile - the configuration file that tslint should use instead of the default tslint.json. A relative file path is resolved relative to the project root.
• ignoreDefinitionFiles - control if TypeScript definition files should be ignored.
• alwaysShowRuleFailuresAsWarnings - always show rule failures as warnings, ignoring the severity configuration in the tslint.json configuration.
• disableNoUnusedVariableRule - disable no-unused-variable rule.
• supressWhileTypeErrorsPresent - supress tslint errors from being reported while other errors are present.
• mockTypeScriptVersion - force tslint to use the same version of TypeScript as this plugin. This will affect other plugins that require the typescript package.

Here a configuration sample:

{
  "compilerOptions": {
    "plugins": [
      { "name": "tslint-language-service",
        "alwaysShowRuleFailuresAsWarnings": false,
        "ignoreDefinitionFiles": true,
        "configFile": "../tslint.json",
        "disableNoUnusedVariableRule": false,
        "supressWhileTypeErrorsPresent": false,
        "mockTypeScriptVersion": false
      }
    ]
  }
}

Editors Support

All editors which consumes tsserver (VSCode >=1.16.1, Sublime, Eclipse, etc) can use tslint-language-service. Here a demo with Eclipse and tslint 5.0.0.

Eclipse

Install typescript.java and you can use the TypeScript Project wizard which configures tslint-language-service.

Visual Studio Code

If you also have the vscode-tslint extension in VS Code installed, please disable it to avoid that files are linted twice.

To use the plugin with VS Code (>=1.16.1):

• If you are using the vscode-tslint extension disable or uninstall it.
• Install typescript, the tslint-language-service, and tslint into your workspace using npm install typescript tslint tslint-language-service.
• Open VS Code on the workspace
• Switch to the Typescript version that is installed locally in the workspace using the version switcher (see below) in the bottom right of the status bar.

The most important differences between the vscode-tslint extension and the tslint-languageservice-plugin are:

• The plugin shares the program representation with TypeScript. This is more efficient than the vscode-tslint extension which needs to reanalyze the document.
• Since vscode-tslint lints one file a time only, it cannot support tslint rules that require the type checker. The language service plugin doesn't have this limitation.
• vscode-tslint provides additional features, please file issue requests for the features you are missing.

Demo

Development Setup

This section describes how to setup your environment so that you can develop and test the language server plugin.

The folder dev contains a project with a tsconfig.json that enables the tslint-languageservice plugin a tslint.json and some test files with rule violations you can use for manual testing.

VS Code

To compile the test for manual testing run npm run devtest, this script compiles the plugin and patches the tslint-language-service module inside the dev folder.

To test open VS Code on the dev folder and use the TypeScript version picker to switch to the local version of TypeScript. This version will use the patched tslint-language-service module.

To debug you use two versions of VS Code, e.g., the stable and the insider version. The idea is that one of them is configured to support attaching a debugger to the Typescript language server:

• Use the insider version for development and open it on the tslint-language-service workspace.
• Use the stable version for debugging opened on the dev folder of the tslint-language service.

To setup the stable version for debugging, you need to set the environment variable TSS_DEBUG to port 5859. In a command prompt/shell:

• make sure that the stable version isn't running already
• set TSS_DEBUG=5859
• cd to the dev folder
• code .

To debug the tslint-language-service plugin press F5. The dev workspace has a launch configuration that attaches through port 5859 to the language server. To set a break point open node_modules\tslint-language-service\out\src\index.js. You have to set the break point in the .js file, but you can step afterwards in the TypeScript source file.